Thin shelled rock crab larva (Grapsus tenuicrustatus)
Copyright 2010 Dennis Kunkel Microscopy, Inc.
Caption: Thin shelled rock crab larva - zoea stage (Grapsus tenuicrustatus). The life cycle of a rock crab begins with a brooding egg that is carried on the female (many attached to pleopods on the female). The egg hatches in to the first larval stage (similar to many other crustaceans), called the zoea stage (5th zoeal stage seen in this image); 5 development zoeal stages occur. These microscopic zoeae are marine pelagic plankton and are generally swept out to sea with currents, as they have very limited swimming abilities. They however can swim short distance with their thoracic appendages. The 5th zoeal stage develops in to the final larval stage called the megalopa. The megalope develops in to a juvenile crab which molts 11-13 times to reach the adult crab stage. The adult stage (male and female) molt and mate once a year. These crabs (often called Natal Lightfoot Crabs) are common on rocky shores in Hawaii and are named for the way they move across the inter-tidal zones. They can be seen scampering in the splash zone and find shelter in rock crevices or water when startled. Magnification*: x27 Type: SEM
*(Magnifications are based on a 35mm slide image of 24mm in the narrow dimension.)